Why are marine ecosystems biologically more diversified than their equivalent terrestrial ecosystems?

On the other hand, terrestrial ecosystems are ecosystems that are found only on landforms. They mainly support a community of organisms and their environment that occurs on the land masses of continents and islands. The base of the food web in the terrestrial ecosystems is occupied by green plants, which are the only organisms capable of utilizing the energy that comes from the sun and inorganic nutrients obtained from the soil to produce organic molecules.1 Even though the tropical rain forest ecosystem is biologically more diversified, the other terrestrial ecosystems, such as tundra (i.e. arctic), taiga (i.e. boreal forests), temperate deciduous forests, Mediterranean shrub-land, mountains, temperate grasslands, tropical savannah, and desert ecosystems are biologically less diversified than their equivalent marine ecosystems.1–5